In Article 157-1 of The Securities Exchange Law, there are completely full of plenty of relevent issues, and so are the studies that has been discussed the materiality of nonpublic information. This study is about to have the discussion in the criteria for materiality of nonpublic information of insider trading. This study will discuss about the criteria for materiality of nonpublic information of insider trading. First, this study discusses laws pertinent to the issue in the United States and in the European Union. Second , examining the Exchange Law and the relevant court decisions decreed in Taiwan during 2016-2017. In the oppinion of the study, it should be adopted the early standard. The purpose of the standard could confer the obligation and warning effects much higher; furthermore, it as well as prevent the court from judging every single case in each particular matters by Consequentialism.